The Validity of Some Popular Readability Formulas

Abstract

This study aimed at exploring the correlation between readers’ evaluation of text-readability on one hand and some
popular readability formula’s (Flesch Reading Ease Readability Formula, Gunning’s Fog-Index of Readability, The SMOG Index
of Readability, Flesch-Kincaid) evaluation of text-readability on the other. This study was conducted with an overall number of
118 participants. The participants were selected from among male and female undergraduate students studying different EFLrelated
majors at the Department of Foreign Languages and Linguistics of IAU, Shiraz Branch. The participants were chosen
using convenient sampling procedure. To achieve the objectives of the study, 5 passages of different readability index were
used. Moreover, a questionnaire aimed at tapping responses from the participants was devised on each passage. Finally, a
number of SPSS analyses were run and the results of the study did not reveal any significant correlations between readers’ and
the formulas’ evaluation of text-readability level. As a conclusion, it seems that those teachers who have used the readability
formulas as valuable measures for evaluating materials to use with their students should use them cautiously. Of course, further
research seems necessary to check the validity of the readability formulas.